U.S. Pat. No. 4,581,297 A describes a method comprising reacting 25 g of hydrobromide of 6-bromohexylamine with 24.2 g of sodium thiosulfate in 580 ml of water, concentrating the obtained reaction solution until its volume was reduced by half, then cooling and isolating the resulting precipitation of S-(6-aminohexyl)thiosulfuric acid by filtering.